This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Prismatic Floral Background No Black
Source GDJ
Prismatic Abstract Geometric Background 5
Source GDJ
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Colour version of the original pattern.
Source Firkin
The image depicts polka dot seamless pattern.
Source Yamachem
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
High detail stone wall with minor cracks and specks.
Source Projecteightyfive